Throughout human history acorns have probably been eaten by indigenous people, and were highly prized by many hunter-gatherer cultures.
The Holm oak is hardy to about -15°C. Some specimens in Ireland were apparently killed by the unusually low temperatures of December 2010
Holm Oak (Quercus ilex)
The principal oak used for human food in the Mediterranean area and in Iberia. Evergreen. Very long lived tree, fully hardy in most parts of Ireland. Will produce first acorns at about ten years